I'm not getting involved in anything as radical as Father Ted!
Whether a demo would be a damp squib I don't know but (a.) I doubt it would bring about "accurate and up-to-the-minute progress reports" (just a hunch!) and (b.) I personally would guess that the Time Capsule idea won't go ahead. Not in Silbury anyway...
As for "a simple non-intrusive ceremony open to all and culminating in the sealing of Silbury once and for all" people are welcome to do what they want but personally I'd rather chew my leg off than go to one of those. Judging by the pictures from the opening event I don't think I have a natural affinity with either of the groups represented - http://www.gazetteandherald.co.uk/search/zoom.php?imid=514612 http://www.gazetteandherald.co.uk/zoom.php?imid=514611
That's the trouble though isn't it? The third group is never invited.